Referring now to FIG. 1, there is shown a top plan view of a prior art a two phase linear CCD sensor 10, which comprises a substrate body 12 of a semiconductor material having therein a plurality of photodetectors 14 arranged in a line. A CCD shift register 16 extends along the line of photodetectors 14. The CCD shift register 16 comprises two sets of gate electrodes 18 and 20. Two gate electrodes 18 and 20, one from each set, are adjacent each photodetector 14. The gate electrodes 18 are all electrically connected together by a metal bus line 22, and the gate electrodes 20 are all electrically connected together by a separate metal bus line 24. A conductive transfer gate 26 extends over the body 12 between the photodetectors 14 and the CCD shift register 16. In the body 12 and in an area adjacent one end of the CCD shift register 16 is an output circuit 28, the details of which are not shown, to which the CCD shift register 16 is connected. The metal bus lines 22 and 24 are connected to a source of voltage (not shown) which is clocked to operate the CCD shift register 16. For long CCDs which are operated at high frequencies, it is desirable to be able to drive the gate electrodes 18 and 20 from both ends of the metal bus lines 22 and 24. For certain types of operations, it is desirable to have a multiple array CCD sensor.
Referring now to FIG. 2, there is shown a top plan view of a multiple array CCD sensor 30 of the prior art formed of three linear CCD sensors 10a, 10b and 10c. Each of the linear CCD sensors 10a, 10b and 10c is identical to the linear CCD sensor 10 shown in FIG. 1 and has bus lines 22a, 24a, 22b, 24b, and 22c and 24c, respectively. In order to minimize the size of the sensor array 30, the CCD sensors 10a, 10b and 10c are made as compact as possible and are provided on a substrate body 12 which is as small as possible. One problem with this approach is that there is not enough room for all of the metal bus lines 22a, 24a, 24b, 22c, 24c to extend to both ends of the sensor array 30. The bus line 24b for the middle CCD sensor 10b has no room to extend around the area of the output circuit 28b. The output circuits 28b and 28c could be spread out (separated) to accommodate the bus lines 22b and 24b of the middle CCD sensor 10b, but this would increase the overall width of the substrate body 12, and potentially lead to amplifier mismatches. The total capacitance of each of the output circuits 28a, 28b and 28c must be designed to be extremely small (typically less than 25 fF). Spreading out the output circuits 28b and 28c to make room for the bus lines 22b and 24b would increase the capacitance and possibly lead to channel-to-channel mismatch in gains. Therefore, it would be desirable to have an arrangement of three linear CCD image sensors on a single substrate body in which all of the bus lines can be extended to both ends of the CCD shift registers while maintaining a substrate body of as small as is reasonably possible.